Hello!
I have just done first check on the L7. I have reassembled the power supply
and have put a 1 Ohm/5W glass enameled resistor in place of the original
0.82 Ohm/2W, because I had nothing else suitable. I don't know if I am
risking too much by putting a 5W job... please, let me know about this.
Well, I have opened the L7 and have mechanically defeated the interlocks
and removed the plate caps. Then I have powered the L7PS and have set the
L7 controls in STANDBY and CW and, finally, power switch to ON. I have seen
how the tubes came to life... and no exploding from the PS... so I think
the trouble which caused the vaporization of previous 0.82 Ohm resistor is
in the tubes, not in the surrounding circuitry (except if there is a
parasitics trouble). Please, feel free to correct me as I am really new in
power amps!
Now I have to connect plate caps and apply power. But one thing I have
noticed is that one of the 3-500Z tubes has something loose inside... if
you just rotate it in your hands, you can clearly heard some metallic
noise. There is nothing visible which moves, so it should be something in
the grid area... I am afraid this means the tube is bad. Could you comment
about this?. I don't want to go further if this is a clear symptom of
damaged tube.
Thanks for your help!
Regards,
JOSE
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73 EB5AGV / EC5AAU
JOSE V. GAVILA
La Canyada - Valencia (SPAIN)
EB5AGV Vintage Radio Site: http://www.geocities.com/eb5agv
European Boatanchors List: http://www.eGroups.com/list/euro_ba_swap
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